Had Throttle Body Cleaned - What A Change! Also, My Power Steerin

[90LS400Lexus]

I have been wanting to get my throttle body cleaned for awhile now, but put it off. The dealer wanted like $120! I took it today to a shop that has about 6 mechanics (been around for years) and always stays busy. The guy that did it (older man) had a 1991 ES250, so we talked alittle about Lexus's, because I stayed in the shop as he did it. :) Hes not really up not up to par though, because he dont think an LS400 was made in 1990 and it started in 1991 and that in 1990 that it was a ES300. I just let him believe it, but we all know 1989 was the first year the LS400 was sold as a 1990 model.

My throttle body was terrible. It was all gummed up. It took him about 30 minutes to get it cleaned out, but he did and man, does it run so much better. That hesitation when I would first accelerate from a stop is gone, as is the "chugging" that I was getting on light acceleration between 35-50 mph as the grades changed.

After that, I ran more errands... pleased with the performance. Also another miracle (though it may be short-lived) is that when I slowed down off of the highway before I got home is that I noticed the steering seemed to be easy to turn... I pulled into my driveway and my power steering is back again! Even when in gear and stopped, I could steer with my pinky for the first time in about 6 weeks. Most of you know the nightmares I have had with my power steering lately. I am wondering if after I cleaned the pump screen that there was air in the lines? Apparently the screen was dirtier than I thought. I just hope it continues to work and not go back out. Its been a strange ordeal thats for sure.

[amcdonal86]

Great news! Keep us posted.

[billydpowell]

AAAAHHHHH the sweet smell of success...... I am proud of you.... you have paid your dues and you are worthy to be congratulated on a job well done...

I sure "hope" with you.

hay I might even clean my throttle body to see what happens....

[90LS400Lexus]

lol. Well I spoke too soon on the steering, because when I left for work this morning it was back to its old ways. :( I never went to the way it was before again today. I guess something is really screwed up with the steering pump or rack. I am not sure. Its like a switch is being thrown on the steering.

Anyway, the car is running very nicely since the throttle body was cleaned. ALL of that hesitation and stumbling is GONE! :) There was even a point where I thought my torque converter was bad because of the lurching... it was all the throttle body causing it.

I priced it to a couple of guys for $3000, but said I would take less since it needs valve cover gaskets and motor mounts for someone picky in the future, but most people probably would not even notice it needs motor mounts. If I sold it for even $3000, its a big loss on my part, but I paid too much for it when I bought it. I have put about 25K miles on it in two years, so maybe that will justify the $1200 loss, but its a little more that since I did replace tranny mount and fan bearing.

I am going to keep it priced at $2800 and may take a slightly less offer, but not much. I feel its worth at least $2600. Accords and Camrys of this generation in nice of condition are selling for that around here.

Yes, I highly recommend to anyone to get your throttle body done, or do it yourself if you know its not been done in awhile. You will not regret it!

[amcdonal86]

A $1200 "loss" over 2 years and 25k miles of driving is not a loss at all! It's simply the cost of transportation.

[90LS400Lexus]

A $1200 "loss" over 2 years and 25k miles of driving is not a loss at all! It's simply the cost of transportation.

Thats what I was thinking too. Could not have rented a car that cheap. ;)

[lexfourcam]

my cars sometimes lunges when it shifts and it also has hesitation between 2-3k rpm. i took a look inside while my intake was off one day and it was black, both sides where black when opened the throttle. I'm thinkin about cleaning it myself.

[90LS400Lexus]

Definitely... thats your problem. You will be amazed!

[curiousB]

I was under the impression dirty throttle body is a solution for erratic idling due to the throttle plate not being able to seal closed fully and thereby creating air leaks which work against the action of the IACV. As such I don't understand what it would do at open throttle positions such as 2-3K RPM. Are you sure you're not ascribing too much benefit to a throttle body cleaning? Definitely a fix for idle issues, but I’m not so sure about the other.

[killerFatty]

I can atest to the value of a good clean TB. I cleaned mine myself and after removing nearly a 1/4 inch of carbon (OK not a 1/4 inch, but close) the whole power band was much smoother. I can't vouch for it fixing any idle issues because I didn't have any, but as far as an improvement in the whole rpm range, its the best bang for your buck. The only thing I can think of that would be better than a TB cleaning is a complete overhaul.

[lexfourcam]

sounds great guys i'm gonna go buy myself a gasket and start taking her apart. i've also had this strange knock/misfire when the car first starts (cold start) if i try to take it over 2k rpm. i was thinkin maybe a valve could be bent. after she warms up it's not noticeable until about 5k rpm. if it is a bent valve, i'm willing to fix the car. it has 120k miles and everything else is great. oh btw the car ran great when i first had the maf unplugged, and now i was thinkin my plugs could be fouled out again due drivin it so long without one. i'm going to buy another one but have yet to find out if it was the harness to the maf or the maf itself. i blew my 3rd 12 and amp. i bought a new one yesterday and boy does it thump now. now i just need to get her running perfect. TIA

[90LS400Lexus]

I was under the impression dirty throttle body is a solution for erratic idling due to the throttle plate not being able to seal closed fully and thereby creating air leaks which work against the action of the IACV. As such I don't understand what it would do at open throttle positions such as 2-3K RPM. Are you sure you're not ascribing too much benefit to a throttle body cleaning? Definitely a fix for idle issues, but I’m not so sure about the other.

I am really not sure. All I know is that on take off, when I hit about 1500 rpms, I would have a "dead" spot and it was not even. Also, when I would be going 35-50 mph and it was in overdrive, if I was changing "grades" of the road, the car would lunge, as if there was slack somewhere. Well, all of that hooplah is completely gone after the throttle body cleaning. I am impressed. I didnt get to enjoy it this evening, because we are in the middle of a snow storm! I left my Lexus setting at the parking lot at work! My uncle brought me home in his 4wd. We have 5 inches of snow here at my house, but some areas have much more... roads are ALL snow covered, numerous power outages, accidents, etc. Its bad.

We are not really used to alot of snow, so its made a mess of things here.

[lexfourcam]

you shoulda seen when the colts came to jax traffic traffic traffic. there was an accident on almost every damn corner and intersection and it had been storming a coulple of days. i've learned to drive very slow in the rain especially since my ls400 doesn't have traction control. my new bridgestone tires have much better traction in the rain then those crappy primewells. i think i'm gonna check my plugs again and see if they're black, then go from there. i've gotta get a new maf really bad.

[killerFatty]

how do you unplug the MAF and still have a running car? I forgot to plug it back in one time when I was working on the car and when I started it, it idle really low and "thumpy" sounding, and when I gave it throttle it died. Is their an advantage to not running a MAF or something?

[90LS400Lexus]

how do you unplug the MAF and still have a running car? I forgot to plug it back in one time when I was working on the car and when I started it, it idle really low and "thumpy" sounding, and when I gave it throttle it died. Is their an advantage to not running a MAF or something?

Not sure. The man just unplugged mine so he could remove the intake so he could clean out the throttle body. He didnt start the car back until everything was back in place.

[CELICA XX]

Was this a SEA FOAM Motor Treatment you did ?

Or did you take apart everything and clean it ?

[90LS400Lexus]

Was this a SEA FOAM Motor Treatment you did ?

Or did you take apart everything and clean it ?

Not sure if you are referring to my post or not, but I didnt personally do it. I took it to a shop. All he did was remove everything to gain access to the throttle body on top of the motor and used a cleaner and rags to clean it. It was dreadful. The red cloths were black when he was finished. :o

[90LS400Lexus]

Its playing games again.... I went and picked it up today and the steering is fine again... so easy to turn. It dont know what it wants to do.

lol. Well I spoke too soon on the steering, because when I left for work this morning it was back to its old ways. :( I never went to the way it was before again today. I guess something is really screwed up with the steering pump or rack. I am not sure. Its like a switch is being thrown on the steering.

[lexfourcam]

i couldnt tell you but if it was plugged in my car wouldnt go above 2500 rpm. i'm probably gonna tinker with it today but my car runs without a maf and it doesnt really idle low. although im sure its running rich due to it not having a sensor to make the proper air to fuel mixture. i just needed some power to get onto the expressway people drive like idiots in jax. my maf has been unplugged since august, so i'm going to look on ebay and buy another one.

[curiousB]

Was this a SEA FOAM Motor Treatment you did ?

Or did you take apart everything and clean it ?

Only way to clean it is to take apart and use some cleaner, rags, and some tools to scrape the crud off. No magic elixir in the gas tank or air intake will clean this stuff. It’s caked on real hard. A good measure of elbow grease is required. Plan a few hours if doing it yourself.

[lexfourcam]

well i just noticed something to make me lean even more towards a bent valve. it was about 45 here in jax this morning which is pretty damn cold for here, and when i started my car it was putt putt putt like it was missing fire or something. after the car warmed up it was fine but the colder it is outside the worse the noise it makes when it first starts.

[curiousB]

I doubt the bent valve theory. Probably something else.

1) Maybe the coolant sensor is broken and the ECU is getting imporper engine temp reading and not correcting fuel mix properly.

2) Broken or dirty MAF sensor. Giving false readings leading to ECU and fuel misture not getting set properly or worse still running in limp mode.

3) Faulty O2 sensors. Leading to car always running in open loop mode (intentionally rich mixture).

4) Faulty fuel pump. Unable to achieve full pressure when cold. As pump runs a while it self heats itself to run ok.

[90LS400Lexus]

Only way to clean it is to take apart and use some cleaner, rags, and some tools to scrape the crud off. No magic elixir in the gas tank or air intake will clean this stuff. It’s caked on real hard. A good measure of elbow grease is required. Plan a few hours if doing it yourself.

Definitely! I stayed in the shop while the man cleaned my throttle body and it was bad. The red cloths were turning black! I could hear it... it sounded like honey being stirred. He actually first sprayed some brake parts cleaner on the cloth, then resorted to some "2+2" stuff... it was called something else, like "gum cutter"? It really started getting it he said. Must have since its running perfectly now. Makes me sad now that I am selling it that its running so good after doing that hesitation and lurching it had the past two years I have owned it. <_<

btw - the CE never came on again... maybe it was adjusting itself or something.

[ggemigniani]

Hey 90LS400Lexus, did you ever get your new steering rack solenoid installed to see if that would fix the intermittent power steering problem?

One alternative fluid you might try is genuine Honda Power Steering Fluid. I know a Toyota technician who uses it in his Corolla's power steering system with good results.

[lexfourcam]

replaced the coolant temp sensor and the o2 sensors not so long ago. the maf sensor doesnt work i know for a fact, but i was suspecting their coulda been a fuel problem because in the upper range rpm range after its warm it does this same action when its cold.